package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.CacheClient;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.RedisData;
import com.hmdp.utils.SystemConstants;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.GeoResult;
import org.springframework.data.geo.GeoResults;
import org.springframework.data.redis.connection.RedisGeoCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.domain.geo.GeoReference;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;

import java.time.LocalDateTime;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static com.hmdp.utils.RedisConstants.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private CacheClient cacheClient;
    @Override
    public Result queryId(Long id) {
        //缓存穿透
        Shop shop = cacheClient.queryWithPassThrough(CACHE_SHOP_KEY, id, Shop.class, this::getById, CACHE_SHOP_TTL,TimeUnit.MINUTES);
        //Shop shop = queryWithPassThrough(id);
        //互斥锁解决缓存击穿
        //Shop shop = queryWithMutex(id);
        //逻辑过期解决缓存击穿
        //Shop shop = queryWithLogicalExpire(id);
        /*Shop shop = cacheClient
                .queryWithLogicalExpire(CACHE_SHOP_KEY, id, Shop.class, this::getById, CACHE_SHOP_TTL, TimeUnit.MINUTES);*/
        if (shop == null) {
            return Result.fail("店铺不存在");
        }
        //7返回
        return Result.ok(shop);
    }
    //private static final ExecutorService CACHE_REBUILD_EXECUTOR = Executors.newFixedThreadPool(10);
    //逻辑过期
    /*public Shop queryWithLogicalExpire(Long id) {
        String key = CACHE_SHOP_KEY + id;
        //1从redis查询商铺缓存
        String shopjson = stringRedisTemplate.opsForValue().get(CACHE_SHOP_KEY + id);
        //2.判断是否存在
        if (StrUtil.isBlank(shopjson)) {
            //3存在，直接返回
            return null;
        }
        //4.命中需要先把json反序列化为对象
        RedisData redisData = JSONUtil.toBean(shopjson, RedisData.class);
        Shop shop= JSONUtil.toBean((JSONObject) redisData.getData(), Shop.class);
        LocalDateTime expireTime = redisData.getExpireTime();
        //5.判断是否过期
        if (expireTime.isAfter(LocalDateTime.now())) {
            //5.1未过期，直接返回店铺信息
            return shop;
        }
        //5.2已过期，需要返回重建
        //6缓存重建
        //6.1获取互斥锁
        String lockkey = LOCK_SHOP_KEY+id;
        boolean isLock = tryLock(lockkey);
        //6.2判断是否获取锁成功
        if (!isLock) {
            //6.3成功开启线程，实现缓存重建
            CACHE_REBUILD_EXECUTOR.submit(()->{
                try {
                    //重建缓存
                    this.saveShop2Redis(id,20L);
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }finally {
                    unLock(lockkey);
                }
            });
        }

        //6.4返回过期的商铺信息
        return shop;
    }*/
    //缓存击穿互斥锁
   /* public Shop queryWithMutex(Long id) {
        String key = CACHE_SHOP_KEY + id;
        //1从redis查询商铺缓存
        String shopjson = stringRedisTemplate.opsForValue().get(CACHE_SHOP_KEY + id);
        //2.判断是否存在
        if (StrUtil.isNotBlank(shopjson)) {
            //3存在，直接返回
            return JSONUtil.toBean(shopjson, Shop.class);
        }
        //命中的是否是空值
        if(shopjson != null){
            return null;
        }
        Shop shop = null;

        try {
            //实现缓存重建
            //4.1获取互斥锁
            boolean isLock = tryLock(LOCK_SHOP_KEY);
            //4.2判断是否获取成功
            if(!isLock){
                //4.3失败，则开启休眠模式
                Thread.sleep(50);
               return queryWithMutex(id);
            }
            //4.4成功，根据id查询数据库
            shop = getById(id);
            //5.不存在返回错误
            if (shop == null) {
                //将空值写入redis
                stringRedisTemplate.opsForValue().set(key, "",RedisConstants.CACHE_NULL_TTL, TimeUnit.MINUTES);
                //返回错误信息
                return null;
            }
            //6存在，写入redis
            stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(shop), RedisConstants.CACHE_SHOP_TTL, TimeUnit.MINUTES);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }finally {
            //7.释放互斥锁
            unLock(LOCK_SHOP_KEY);
        }
        //8返回
        return shop;
    }*/

    //创建互斥锁
   /* private boolean tryLock(String key) {
        Boolean flag = stringRedisTemplate.opsForValue().setIfAbsent(key, "1", 10L, TimeUnit.SECONDS);
        return BooleanUtil.isTrue(flag);
    }
    //释放互斥锁
    private void unLock(String key) {
        stringRedisTemplate.delete(key);

    }*/

    //缓存穿透
    /*public Shop queryWithPassThrough(Long id) {
        String key = CACHE_SHOP_KEY + id;
        //1从redis查询商铺缓存
        String shopjson = stringRedisTemplate.opsForValue().get(CACHE_SHOP_KEY + id);
        //2.判断是否存在
        if (StrUtil.isNotBlank(shopjson)) {
            //3存在，直接返回
            return JSONUtil.toBean(shopjson, Shop.class);
        }
        //命中的是否是空值
        if(shopjson != null){
            return null;
        }

        //4不存在，根据id查询数据库
        Shop shop = getById(id);
        //5.不存在返回错误
        if (shop == null) {
            //将空值写入redis
            stringRedisTemplate.opsForValue().set(key, "",RedisConstants.CACHE_NULL_TTL, TimeUnit.MINUTES);
            //返回错误信息
            return null;
        }
        //6存在，写入redis
        stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(shop), RedisConstants.CACHE_SHOP_TTL, TimeUnit.MINUTES);
        //7返回
        return shop;
    }*/

    /*public void saveShop2Redis(Long id,Long expireSeconds) {
        //1.查询店铺数据
        Shop shop = getById(id);
        //2封装逻辑过期时间
        RedisData redisData = new RedisData();
        redisData.setData(shop);
        redisData.setExpireTime(LocalDateTime.now().plusSeconds(expireSeconds));
        //写入Redis
        stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,JSONUtil.toJsonStr(redisData));

    }*/

    @Override
    @Transactional
    public Result update(Shop shop) {
        Long id = shop.getId();
        if (id == null) {
            return Result.fail("店铺id不能为空");
        }
        //1.更新数据库
        updateById(shop);
        //2.删除缓存
        stringRedisTemplate.delete(CACHE_SHOP_KEY + shop.getId());
        return Result.ok();
    }

    @Override
    public Result queryShopType(Integer typeId, Integer current, Double x, Double y) {
        //1.是否需要根据坐标查询
        if (x==null || y==null) {
            //不需要坐标查询，按数据库查询
            Page<Shop> page = query()
                    .eq("type_id", typeId)
                    .page(new Page<>(current, SystemConstants.DEFAULT_PAGE_SIZE));
            // 返回数据
            return Result.ok(page.getRecords());
        }
        //2.计算分页参数
        int from = (current-1)*SystemConstants.DEFAULT_PAGE_SIZE;
        int end = current*SystemConstants.DEFAULT_PAGE_SIZE;

        //3.查询redis、按照距离排序、分页。结果：shopid、distance
        String key = SHOP_GEO_KEY+typeId;
        GeoResults<RedisGeoCommands.GeoLocation<String>> results = stringRedisTemplate.opsForGeo()//GEOSEARCH BYLONLAT x y BYRADTUS 10 WITHDISTANCE
                .search(
                        key,
                        GeoReference.fromCoordinate(x, y),
                        new Distance(5000),
                        RedisGeoCommands.GeoSearchCommandArgs.newGeoSearchArgs().includeDistance().limit(end)
                );
        //4.解析出id
        if (results == null) {
            return Result.ok(Collections.emptyList());
        }
        List<GeoResult<RedisGeoCommands.GeoLocation<String>>> list = results.getContent();
        if (list.size()<=from){
            //没有下一页了，结束
            return Result.ok(Collections.emptyList());
        }
        //4.1截取from~end的部分
        List<Long> ids = new ArrayList<>(list.size());
        Map<String,Distance> distanceMap = new HashMap<>(list.size());
        list.stream().skip(from).forEach(result -> {
            //4.2获取店铺id
            String shopIdStr = result.getContent().getName();
            //System.out.println(shopIdStr);
            ids.add(Long.valueOf(shopIdStr));
            //4.3获取距离
            Distance distance = result.getDistance();
            distanceMap.put(shopIdStr, distance);
        });
        //System.out.println(ids);
       // System.out.println(distanceMap);
        //5.根据id查询Shop
        String idStr = StrUtil.join(",",ids);
        List<Shop> shops = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();
        for (Shop shop : shops) {
            shop.setDistance(distanceMap.get(shop.getId().toString()).getValue());
        }
        //6.返回

        return Result.ok(shops);
    }
}
